At one time the crucial phase of surgical illness was thought to be the anesthesia itself, with the chance of survival depending in large measure upon the patient's response to anesthetic agent. More modern thought holds that while the parameters of anesthesia during the operation are of high importance, pre-anesthesia and to perhaps a greater extent post-anesthetic care plays a great part in determining whether the outcome will be satisfactory. It is an object of the present invention to provide techniques which facilitate the perioperative anesthesia and analgesia treatment continuum. Modern practice dictates choice of an anesthetic agent and procedure based upon several relevant risk considerations, including the age, prior anesthetic experience and emotional condition of the patient, habits and skill of the surgeon, the patient's physical position required for the procedure, and the need to avoid agents or techniques which can unjustifiably be implicated if a complication were to arise. Indeed, the asthenic, the elderly and the chronically ill will generally require minimal anesthesia virtually irrespective of the other conditions. Even the robust, however, who generally will tolerate high levels of anesthetic concentration, often will benefit from relatively minimal though adequate concentrations of anesthetic.
It is a further object of the present invention to provide techniques which allow minimum administration of anesthetic agents. The evolution of anesthetic practice has progressed to ever more complex physiological mechanisms, and a huge variety of agents, administrative techniques, and brands. For example, originally the anesthesia choice lay among ether, nitrous oxide, or chloroform, straightforwardly administered with simple devices. More recently, with proliferation of highly specialized agents, it has become standard practice to give combinations of agents in a balanced technique, each agent for a specific purpose --regional anesthesia for analgesia and muscle relaxation, an appropriate agent administered intravenously for loss of consciousness, and for a suitable inhalant for maintenance of unconsciousness. Not surprisingly, proliferation of anesthetic agents, and administration of a combination of agents in balanced technique, each agent for a specific purpose, increases the risk of untoward reactions by the patient. Indeed, some studies have indicated that 13% of patients admitted to a medical ward suffer some kind of unusual drug reaction, and many are admitted to the hospital for that reason alone. The average out-patient was found to take about six different drugs habitually, while the very ill hospitalized patient may be given as many as twenty. Thus, the possibiltiy for interaction among drugs is considerable, and anesthetics are no exception. Further, straightforward reactions may be genetic in origin, such as perhaps may be true of malignant hyperpyrexia during anesthesia. It is an object of the present invention to minimize untoward reactions occasioned by plural anesthesia agents, or with other drugs or agents. Another problem presented to the anesthetist in particular but also to the surgical team, in general, is presented by the habitual user of drugs or alcohol, who may have vastly altered tolerance to drugs in general and anesthetics in particular.
It is a summary object of the present invention to provide techniques whereby the anesthesiologist, attending physicians, and the surgical team may properly and adequately conduct a surgical procedure, alleviate patient discomfort or sensation, and maintain the patient after surgery, while minimizing risks, trauma, untoward drug interaction and associated occasional adverse effects of anesthesia.